Mobile pressure cleaning systems are in widespread use because of their effectiveness in cleaning exterior surfaces that are soiled by exposure to airborne dirt, oils, acids and other pollutants as well as by vandalism. Interior surfaces, machinery, commercial road vehicles, boats and the like, can likewise be cleaned to restore their appearance and arrest corrosive and otherwise harmful effects of accumulated dirt, pollution and the like.
A successful arrangement of a known mobile pressure cleaning system is shown, for example, in U.S. Pat. No. 4,821,958, hereby incorporated by reference, assigned to the assignee of the present invention. The patent discloses a pressure cleaning unit mounted within a mass-produced commercial utility van. The unit includes a prime mover, typically a diesel engine, driving a pair of high-pressure pumps. One of the pumps is arranged to supply cold or hot water with or without chemical additives such as acids, alkalines, detergents and waxes. The second pump is arranged to exclusively supply high pressure cold rinse water. Suitable tanks for water, chemical additives, fuel, and a water heater are also included in the vehicle. It has been difficult to package the described hardware into a unit that fits comfortably within a production van with generous water and chemical storage capacity and, at the same time, provide high accessibility to the equipment for maintenance and repair. Conventionally, the high pressure cleaning fluid delivery system enabled one operator to apply various chemicals, but a second operator was restricted to only application of a cold water rinse. Another disadvantage of some previous installations is that they have required two fuel storage systems to accommodate diesel fuel for the engine and kerosene for the water heating. Moreover, earlier water heater arrangements have been arranged horizontally and while affording acceptable performance, are somewhat less efficient and require higher maintenance than vertically arranged heaters.